Supervised classification for a family of Gaussian functional models

In the framework of supervised classification (discrimination) for functional data, it is shown that the optimal classification rule can be explicitly obtained for a class of Gaussian processes with "triangular" covariance functions. This explicit knowledge has two practical consequences. First, the consistency of the well-known nearest neighbors classifier (which is not guaranteed in the problems with functional data) is established for the indicated class of processes. Second, and more important, parametric and nonparametric plug-in classifiers can be obtained by estimating the unknown elements in the optimal rule. The performance of these new plug-in classifiers is checked, with positive results, through a simulation study and a real data example.Comment: 30 pages, 6 figures, 2 table

Institucions per maridar òrfenes i donzelles pobres a la València del segle XVII. L'administració fundada per Lluís Beltran

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Social Exclusion and Convergence in the EU: An Assessment of the Europe 2020 Strategy

Economic convergence has long been a declared objective of the EU and considered the fundamental mechanism for achieving socioeconomic cohesion. The recent economic crisis had an uneven impact across EU countries and brought a halt to the process of economic and social convergence. In response to this situation, the Europe 2020 strategy, launched in 2010, aimed to deliver social and territorial cohesion in the Member States. In this paper we evaluate the poverty and social exclusion pillar of the Europe 2020 strategy by analysing whether it has promoted convergence across the EU countries in the indicators devised to capture risk of poverty, severe material deprivation, and the number of persons living in households with very low work intensity. Our results for all three rates indicate that convergence occurs in heterogeneous clubs that do not follow a geographic east‒west or south‒north pattern. Convergence within each club, especially for the severe deprivation rate, takes place by means of a catching-up process, with Eastern European levels converging on the Western levels. Finally, not only is there club convergence, but there is no tendency for the clubs to convergence. Poverty and social cohesion indicators show a multi-speed Europe, casting doubt on the sustainability of the overall convergence process in the EU

Nonlinear trend stationary of real exchange rates: The case of the Mediterranean countries

The aim of this article is to provide additional evidence on the fulfilment of the Purchasing Power Parity hypothesis in the so-called Mediterranean countries. In order to test for the empirical validity of such hypothesis, we have applied two types of unit root tests. The first group is due to Bierens (1997) who generalizes the alternative hypothesis to nonlinear trend stationarity and, the second is the Leybourne, Newbold and Vougas (1998) approach that uses a nonlinear specification for the intercept and slope in order to detrend the series. The results suggest that the evidence in favour of the Purchasing Power Parity hypothesis increases when we allow for nonlinear alternatives.purchasing power parity, real exchange rate, unit roots, structural change, nonlinearity

Do process innovations boost SMEs productivity growth?

In this paper we explore in depth the effect of process innovations on total factor productivity growth for small and medium enterprises (SMEs), taking into account the potential endogeneity problem that may be caused by self selection into these activities. First, we analyse whether the ex-ante most productive SMEs are those that start introducing process innovations; then, we test whether process innovations boost SMEs productivity growth using matching techniques to control for the possibility that selection into introducing process innovations may not be a random process. We use a sample of Spanish manufacturing SMEs for the period 1991-2002, drawn from the Encuesta sobre Estrategias Empresariales. Our results show that the introduction of process innovations by a first-time process innovator yields an extra productivity growth as compared to a non-process innovator, and that the life span of this extra productivity growth has an inverted U-shaped form. En este artículo se exploran los posibles efectos de la introducción de innovaciones de proceso en el crecimiento de la productividad de las pequeñas y medianas empresas (PYMES). Para ello se presta especial atención a la existencia de un problema de selección no aleatorio en la implementación de tales innovaciones. En primer lugar, se analiza si son aquellas empresas ex-ante más productivas las que introducen innovaciones de proceso. A continuación, se utilizan técnicas de matching para contrastar si la implementación de innovaciones de proceso acelera el crecimiento de la productividad de las PYMES. La utilización de técnicas de matching permite controlar la posible existencia de un proceso de selección no aleatorio en la implementación de innovaciones de proceso. El análisis empírico se lleva cabo usando una muestra de PYMES manufactureras españolas extraída de la Encuesta sobre Estrategias Empresariales. Nuestros resultados muestran que la implementación de innovaciones de proceso por parte de PYMES sin experiencia previa en la introducción de tales innovaciones, produce un crecimiento extra de la productividad de estas PYMES en comparación con el de aquellas PYMES que no implementan innovaciones de proceso. Adicionalmente, nuestros resultados sugieren la existencia de una relación en forma de U invertida entre el crecimiento extra de la productividad y el tiempo transcurrido desde la introducción de la innovación de proceso.innovaciones de proceso, PTF, dominancia estocástica, técnicas de matching. process innovations, TFP, stochastic dominance, matching techniques.

Development and Experimental Validation of a Dynamic Model for a Fresnel Solar Collector

this paper presents a lumped parameter dynamic model of a Fresnel collector field of a solar refrigeration plant. The plant is located in the Escuela Superior de Ingenieros of the University of Seville. The dynamic model parameter model developed can be used as a control model or as a simulation tool to test controllers. The lumped parameters have been determined by using real data from the plant in different operating conditions. The model has been validated against a data validation set obtained from the plant. The model has shown to reproduce the system behavior with a good compromise in accuracy and model complexity

REDOX CELL HYDRODYNAMIC MODELLING: TOWARDS REAL IMPROVED GEOMETRY BASED ON CFD ANALYSIS

[EN] Redox cell is an assembly consisting of electrodes surrounded by a volume of electrolyte (liquid). The redox cell device stores electrical energy with full of high acid flows and this acidity causes big difficulties for physical modeling. To overcome this problem, numerical and experimental analysis of those flows in a real redox cell have been developed and here described. A methodology to improve redox cell performance based on the analysis of the electrolyte flow is proposed. Improvements in the flow uniformity are achieved by means of the definition of some designed parameters based on CFD analysis. The depicted methodology is applied to a specific redox cell geometry for improving authors¿ previous designs. This article quantifies parameters for this particular case and the proposed improvements. The considered CFD model is also validated with experimental data using a real scale cell built in transparent material. The convergence between experimental and numerical results is fairly good. Finally, the geometry designed based on this proposed methodology presents 0% dead zones or recirculations in the membrane area, which will definitely improve the overall interchange efficiency of the cell. This validated methodology is presented for a real future design strategy of these sorts of devices.Escudero Gonzalez, J.; López Jiménez, PA. (2014). REDOX CELL HYDRODYNAMIC MODELLING: TOWARDS REAL IMPROVED GEOMETRY BASED ON CFD ANALYSIS. Engineering Applications of Computational Fluid Mechanics. 8(3):435-446. doi:10.1080/19942060.2014.11015527S43544683Bannari A, Cirtiu C, Kerdouss F, Proulx P, Menard H (2006). Turbulence intensity in an electrochemical cell: effect on reactor performance.Chemical Engineering and Processing: Process Intensification45:471–480.Bard A, Faulkner L (2001).Electrochemical Methods. Wiley.Castelain C, Mokrani A, Legentilhomme P, Peerhossaini H (1997). 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Redox cell hydrodynamic modelling, simulation and experimental validation.Engineering Applications of Computational Fluid Mechanics7(2):168–181.Escudero-González, J., & López-Jiménez, P. A. (2014). Iron redox battery as electrical energy storage system in the Spanish energetic framework. International Journal of Electrical Power & Energy Systems, 61, 421-428. doi:10.1016/j.ijepes.2014.03.067Eyer, James M, Corey, Garth P, Iannucci, Joseph J (2004). Sponsoring Organization: USDOE 2004.Frias-Ferrer A (2004).Optimización de la Hidrodinámica de Reactores Electroquímicos:Empleo de Métodos Experimentales y Numéricos. Thesis. Universidad de Alicante.Jörissen L, Frey H (2009). ENERGY | Energy storage.Encyclopedia of Electrochemical Power Sources215–231.Kondoh J, Ishii I, Yamaguchi H, Murata A, Otani K, Sakuta K, Higuchi N, Sekine S, Kamimoto M (2010). Electrical energy storage systems for energy networks.Energy Conversion and Management41:1863–1874.Mellentine J (2011).Performance Characterization and Cost Assessment of an Iron Hybrid Flow Battery. Thesis. University of Iceland.Moore S, David (2003).The Basic Practice of Statistics, 3rd Edition. New York: W,H, Freeman and Company.Navidi W (2006).Estadística Para Ingenieros y Científicos, 1st Edition. New York: McGraw-Hill Companies Inc.Parker C (2009). APPLICATIONS – STATIONARY | Energy storage systems: batteries.Encyclopedia of Electrochemical Power Sources53–64.Rahman F, Rehman S, Abdul-Majeed M (2012). Overview of energy storage systems for storing electricity from renewable energy sources in Saudi Arabia.Renewable and Sustainable Energy Reviews16:274–283.Reddy T (2002).Linden’s Handbook of Batteries, 3rd Edition. McGraw-Hill Professional,Scamman D, Reade G, Roberts E (2009). 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Applet de Física. Polarización lineal: Ley de Malus.

Quan un feix de llum incideix sobre un conjunt de dos o més polaritzadors lineals la intensitat transmesa, que depèn de l'angle relatiu entre ells, es pot expressar mitjançant la llei de Malus. En aquesta simulació es pot veure l'efecte sobre la intensitat del feix incident de l'actuació d'un, dos i fins a tres polaritzadors lineals, dels quals podem seleccionar el seu nombre i variar l'orientació del seu eix de transmissió, comprovant d'aquesta manera el compliment de la llei de Malus.Cuando un haz de luz incide sobre un conjunto de dos o más polarizadores lineales la intensidad transmitida, que depende del ángulo relativo entre ellos, se puede expresar mediante la ley de Malus. En esta simulación se puede ver el efecto sobre la intensidad incidente de la actuación de uno, dos y hasta tres polarizadores lineales, de los que podemos seleccionar su número y variar la orientación de su eje de transmisión, comprobando de este modo el cumplimiento de la ley de Malus.When a light beam impinges on a set of two or more linear polarizers the transmitted intensity, which depends on the relative angle between them, can be expressed by Malus’law. In this simulation is possible to see the effect of one, two or three linear polarizers on the incident light beam intensity. We can select the number of polarizers and the orientation of its transmission axis, thereby checking the fulfillment of Malus’law

Experiencias de planeación organizacional en centros y grupos de investigación.

Este escrito ofrece una visión acercadel significado que tiene un procesode planeación organizacional parauna institución, y describe y analizasu aplicación en entidades de investigación.Para este efecto se presentauna parte teórica y un análisis deentrevistas a centros y grupos de investigación.Al final del escrito se destacala relación que pareciera existirentre el proceso de planeación de cadacentro o grupo y su proceso de consolidacióncomo institución.

Cost and performance of carbon risk in socially responsible mutual funds

Investors and other financial actors are attracted by the role of socially responsible (SR) mutual funds in the transition to a low-carbon economy. In response to the demand for more information, Morningstar reported the level of carbon risk of funds by using the following indicators: Carbon Risk, Carbon Management, Carbon Operations risk and Carbon Exposure. Dealing with a sample of 3370 equity SR mutual funds worldwide from 2017 to 2021, this study analyzes the relationships between these indicators and the expense ratio and performance of the funds. In general, the results point to funds with lower carbon scores that have lower fees and perform better than those with higher scores. Considering the effects of the COVID-19 crisis, this evidence holds true for most of the sample period analyzed. With a spatial analysis, although the evidence generally holds, regional differences are found. Thus, funds that invest in the USA and Canada are on average cheaper and show lower carbon scores, while funds that are oriented to other areas, such as emerging markets, are more expensive and show higher scores. In summary, there is good news for the utility function of the investor and the planet: Green investing is cheaper and better